context("eigen_centrality") test_that("eigen_centrality works", { library(igraph) kite <- graph_from_literal(Andre - Beverly:Carol:Diane:Fernando, Beverly - Andre:Diane:Ed:Garth, Carol - Andre:Diane:Fernando, Diane - Andre:Beverly:Carol:Ed:Fernando:Garth, Ed - Beverly:Diane:Garth, Fernando - Andre:Carol:Diane:Garth:Heather, Garth - Beverly:Diane:Ed:Fernando:Heather, Heather - Fernando:Garth:Ike, Ike - Heather:Jane, Jane - Ike) evc <- round(eigen_centrality(kite)$vector, 3) expect_that(evc, equals(structure(c(0.732, 0.732, 0.594, 1, 0.827, 0.594, 0.827, 0.407, 0.1, 0.023), .Names = c("Andre", "Beverly", "Carol", "Diane", "Fernando", "Ed", "Garth", "Heather", "Ike", "Jane")))) ## Eigenvector-centrality, small stress-test is.principal <- function(M, lambda, eps=1e-12) { abs(eigen(M)$values[1] - lambda) < eps } is.ev <- function(M, v, lambda, eps=1e-12) { max(abs(M %*% v - lambda * v)) < eps } is.good <- function(M, v, lambda, eps=1e-12) { is.principal(M, lambda, eps) && is.ev(M, v, lambda, eps) } for (i in 1:1000) { G <- sample_gnm(10, sample(1:20, 1)) ev <- eigen_centrality(G) expect_true(is.good(as_adj(G, sparse=FALSE), ev$vector, ev$value)) } })
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